1. Field
One aspect relates to a method of screening a protein involved in efficiently producing 1,4-BDO. Another aspect relates to a microorganism the nucleic acid encoding the protein screened by the method. Another aspect also relates to a method of producing 1,4-BDO at a high efficiency using the microorganism.
2. Description of the Related Art
1,4-butandiol (1,4-BDO) is used not only as a solvent for manufacturing plastics and fiber but also as a raw material for producing fiber such as spandex. About 1.3 million tons of 1,4-BDO is produced in a year worldwide from petroleum-based materials such as acetylene, butane, propylene, and butadiene. In addition, about 6% of consumption increase is anticipated each year. 1,4-butandiol is important as it is used throughout the entire chemical industry for the production of various chemicals such as polymers, solvents, and fine chemistry intermediates. Most of the chemicals having a carbon number of four are currently synthesized by being derived from 1,4-butandiol or maleic anhydride, but the chemical production process needs to be improved or replaced by a newly developed process as production costs are increasing due to rising oil prices. Thus, biological processes using microorganisms are suggested as the alternative processes.
Different from the method of producing 1,4-BDO chemically, Genomatica Inc. established in 2011 a biosynthetic pathway of producing 1,4-BDO using succinyl-CoA synthetase (Cat1), succinate semialdehyde dehydrogenase (SucCD), NAD-dependent 4-hydroxybutyrate dehydrogenase (4Hbd), 4-hydroxybutyryl CoA:acetyl-CoA transferase (Cat2), and alcohol dehydrogenase (AdhE2) genes in an Escherichia coli. However, there has been an attempt to establish a new biosynthetic pathway by altering the biological pathways which have already been shown in an Escherichia coli in order to produce 1,4-BDO more efficiently. The attempt is much focused on discovering enzymes of high efficiency by inducing various genetic mutations in enzyme genes.
However, such an approach alone is limited in effectively discovering a protein or a gene related to producing of 1,4-BDO. A novel approach was tried to solve the problem, and the genes screened by the approach were verified to enable a significant increase of 1,4-BDO production.